Question 1

What agencies develop the zone interpretive criteria?

Accepted Answer

A)   CDC and USAMRIID
B)   U.S. FDA and CDC
C)   FDA and CLSI
D)   CLSI and CDCE) C) and D)
F) All of the above

Question 2

When should antimicrobial susceptibility testing be performed on a bacterial isolate from a clinical specimen?

Accepted Answer

A)   When the isolate is determined to be a probable cause of the patient's infection
B)   When the susceptibility of the isolate to particular antimicrobial agents cannot be reliably predicted
C)   When the organism is part of the normal microbiota
D)   Both A and BE) A) and B)
F) A) and C)

Question 3

All the following organisms often produce  β\betaβ -lactamase, except

Accepted Answer

A)   Haemophilus influenzae.
B)   Neisseria gonorrhoeae.
C)   Moraxella catarrhalis.
D)   Neisseria meningitidis. E) All of the above
F) A) and C)

Question 4

A man goes to his doctor because he has a cloudy substance dripping from his penis. A Gram stain is performed and gonorrhea is isolated. What is the drug of choice to treat this infection?

Accepted Answer

A)   Gentamicin
B)   Erythromycin
C)   Vancomycin
D)   CeftriaxoneE) A) and B)
F) B) and C)

Question 5

If the MIC or zone size is interpreted as intermediate using the latest CLSI tables

Accepted Answer

A)   the clinical interpretation of the result is that the patient's infecting organism should respond to therapy with that antimicrobial agent using the dosage normally recommended for that type of infection and that species.
B)   the patient's infecting organism is unlikely to be inhibited by the usually achievable concentrations of the antimicrobial agent based on the dosages normally used with that drug.
C)   the patient's infecting organism is likely to require the maximum amount of antimicrobial or more than can be achieved and for which the clinical response is likely to be less than with a susceptible strain.
D)   None of the aboveE) A) and C)
F) A) and B)

Question 6

What is the principle of the Etest?

Accepted Answer

A)   Turbidimetry
B)   Establishing an antimicrobial density gradient in agar
C)   Carbon dioxide concentration
D)   Redox indicator systemE) None of the above
F) All of the above

Question 7

What is the most critical step in any susceptibility test?

Accepted Answer

A)   Plate streaking
B)   Organism isolation
C)   Gram stain identification
D)   Inoculum preparationE) None of the above
F) A) and B)

Question 8

A 12-year-old girl goes to the doctor complaining of a sore throat, fever, headache, and general malaise. The doctor does a quick strep test that is positive for group A  β\betaβ -hemolytic Streptococcus. No antibiotic testing is needed because Streptococcus is

Accepted Answer

A)   universally susceptible to penicillin.
B)   universally susceptible to erythromycin.
C)   not treated in throat cultures.
D)   not considered a pathogen in the throat. E) None of the above
F) All of the above

Question 9

A drug will generally inhibit multiplication of the bacteria so that the patient's immune defense mechanisms are no longer overwhelmed when

Accepted Answer

A)   all the debris and necrotic cells are removed.
B)   the drug concentration exceeds the MIC for the microbe.
C)   the patient is not infected with a gram-negative rod.
D)   two synergistic drugs are used to kill the bacteria.E) A) and B)
F) A) and D)

Question 10

After the plate is incubated in the Kirby-Bauer test, what occurs?

Accepted Answer

A)   The plate is tested to make sure an isolated organism grew on the plate.
B)   The diameter of each inhibition zone for each antibiotic is measured using a ruler or caliper.
C)   The amount of carbon dioxide in the plate is measured to ensure confluent organism growth.
D)   None of the above.E) B) and D)
F) None of the above

Question 11

A combination of antimicrobials is said to show synergism if

Accepted Answer

A)   its antibacterial activity is significantly greater than that of the single agents.
B)   its antibacterial activity is significantly less than that of the single agents.
C)   the antibacterial activity is sustained for a much prolonged time compared with the single agents.
D)   the antibacterial activity is sustained for a much shorter time compared with the single agents.E) C) and D)
F) B) and C)

Question 12

What McFarland standard provides turbidity comparable to that of a bacterial suspension containing approximately 1.5  ×	imes×  108 colony-forming units (CFU) /mL?

Accepted Answer

A)   1.0
B)   1.5
C)   0.5
D)   2.0 E) A) and C)
F) A) and D)

Question 13

What is a mechanism for ensuring the testing personnel are proficient in their tasks?

Accepted Answer

A)   Supervisory review of reported results
B)   Self-assessment checklists
C)   Periodic competency testing through proficiency surveys
D)   All of the aboveE) B) and C)
F) C) and D)

Question 14

What broth is recommended in the tube dilution MIC tests?

Accepted Answer

A)   Trypticase soy
B)   Mueller-Hinton
C)   Columbia
D)   Cooked meatE) A) and B)
F) B) and D)

Question 15

What principle does the VITEK series use to determine antimicrobial susceptibility?

Accepted Answer

A)   Turbidimetry
B)   Redox indicator system
C)   Hydrolysis of a fluorogenic substrate
D)   Carbon dioxide concentrationE) C) and D)
F) None of the above

Question 16

In vitro testing conditions that can be modified to enhance the expression of oxacillin resistance include all the following, except

Accepted Answer

A)   use Mueller-Hinton media.
B)   making final test readings after a full 24 hours of incubation.
C)   incubation of tests at temperatures no greater than 35 °\degree°  C.
D)   preparation of inocula using the direct inoculum suspension procedure. E) A) and B)
F) A) and C)

Question 17

Therapy of disseminated meningococcal infections and various types of gonococcal (GC)  infections are

Accepted Answer

A)   hard to treat and require special  β\betaβ -lactamase tests.
B)   an important public health concern, so a full spectrum of antimicrobial susceptibility testing is always performed.
C)   generally empiric based on recommendations of CDC.
D)   None of the above E) None of the above
F) All of the above

Question 18

Why are aminoglycosides not an effective treatment for meningitis?

Accepted Answer

A)   They do not cross the blood-brain barrier.
B)   They are nephrotoxic and will harm the patient's kidneys.
C)   They are ototoxic and will harm the patient's ears.
D)   They are not effective against Neisseria, Streptococcus, or Haemophilus.E) A) and D)
F) B) and C)

Question 19

What is the approximate final concentration of organisms in each well of a microdilution tray?

Accepted Answer

A)   3  ×	imes×  105 CFU/mL
B)   1  ×	imes×  105 CFU/mL
C)   4  ×	imes×  105 CFU/mL
D)   5  ×	imes×  105 CFU/mL E) A) and B)
F) A) and C)

Question 20

In this method of antimicrobial susceptibility testing, specific volumes of various concentrations of antimicrobial solutions are dispensed into premeasured volumes of molten and cooled agar, which is subsequently poured into standard Petri dishes. Organisms are inoculated onto the plate. What type of antimicrobial susceptibility testing is this?

Accepted Answer

A)   Macrodilution
B)   Broth dilution
C)   Disk diffusion
D)   Agar dilutionE) None of the above
F) C) and D)

Exam 13: Antimicrobial Susceptibility Testing

What is the principle of the Etest?

Correct Answer
verified

What is the approximate final concentration of organisms in each well of a microdilution tray?

Correct Answer
verified

A drug will generally inhibit multiplication of the bacteria so that the patient's immune defense mechanisms are no longer overwhelmed when

Correct Answer
verified

After the plate is incubated in the Kirby-Bauer test, what occurs?

Correct Answer
verified

What McFarland standard provides turbidity comparable to that of a bacterial suspension containing approximately 1.5 $\times$ 10⁸ colony-forming units (CFU) /mL?

Correct Answer
verified

All the following organisms often produce $\beta$ -lactamase, except

Correct Answer
verified

A man goes to his doctor because he has a cloudy substance dripping from his penis. A Gram stain is performed and gonorrhea is isolated. What is the drug of choice to treat this infection?

Correct Answer
verified

What is a mechanism for ensuring the testing personnel are proficient in their tasks?

Correct Answer
verified

A 12-year-old girl goes to the doctor complaining of a sore throat, fever, headache, and general malaise. The doctor does a quick strep test that is positive for group A $\beta$ -hemolytic Streptococcus. No antibiotic testing is needed because Streptococcus is

Correct Answer
verified

Why are aminoglycosides not an effective treatment for meningitis?

Correct Answer
verified

Correct Answer
verified

What is the most critical step in any susceptibility test?

Correct Answer
verified

What agencies develop the zone interpretive criteria?

Correct Answer
verified

What principle does the VITEK series use to determine antimicrobial susceptibility?

Correct Answer
verified

Therapy of disseminated meningococcal infections and various types of gonococcal (GC) infections are

Correct Answer
verified

If the MIC or zone size is interpreted as intermediate using the latest CLSI tables

Correct Answer
verified

A combination of antimicrobials is said to show synergism if

Correct Answer
verified

When should antimicrobial susceptibility testing be performed on a bacterial isolate from a clinical specimen?

Correct Answer
verified

What broth is recommended in the tube dilution MIC tests?

Correct Answer
verified

In vitro testing conditions that can be modified to enhance the expression of oxacillin resistance include all the following, except

Correct Answer
verified

Exam 13: Antimicrobial Susceptibility Testing

What is the principle of the Etest?

Correct AnswerverifiedShow Answer

What is the approximate final concentration of organisms in each well of a microdilution tray?

Correct AnswerverifiedShow Answer

A drug will generally inhibit multiplication of the bacteria so that the patient's immune defense mechanisms are no longer overwhelmed when

Correct AnswerverifiedShow Answer

After the plate is incubated in the Kirby-Bauer test, what occurs?

Correct AnswerverifiedShow Answer

What McFarland standard provides turbidity comparable to that of a bacterial suspension containing approximately 1.5 ×\times× 108 colony-forming units (CFU) /mL?

Correct AnswerverifiedShow Answer

All the following organisms often produce β\betaβ -lactamase, except

Correct AnswerverifiedShow Answer

A man goes to his doctor because he has a cloudy substance dripping from his penis. A Gram stain is performed and gonorrhea is isolated. What is the drug of choice to treat this infection?

Correct AnswerverifiedShow Answer

What is a mechanism for ensuring the testing personnel are proficient in their tasks?

Correct AnswerverifiedShow Answer

A 12-year-old girl goes to the doctor complaining of a sore throat, fever, headache, and general malaise. The doctor does a quick strep test that is positive for group A β\betaβ -hemolytic Streptococcus. No antibiotic testing is needed because Streptococcus is

Correct AnswerverifiedShow Answer

Why are aminoglycosides not an effective treatment for meningitis?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

What is the most critical step in any susceptibility test?

Correct AnswerverifiedShow Answer

What agencies develop the zone interpretive criteria?

Correct AnswerverifiedShow Answer

What principle does the VITEK series use to determine antimicrobial susceptibility?

Correct AnswerverifiedShow Answer

Therapy of disseminated meningococcal infections and various types of gonococcal (GC) infections are

Correct AnswerverifiedShow Answer

If the MIC or zone size is interpreted as intermediate using the latest CLSI tables

Correct AnswerverifiedShow Answer

A combination of antimicrobials is said to show synergism if

Correct AnswerverifiedShow Answer

When should antimicrobial susceptibility testing be performed on a bacterial isolate from a clinical specimen?

Correct AnswerverifiedShow Answer

What broth is recommended in the tube dilution MIC tests?

Correct AnswerverifiedShow Answer

In vitro testing conditions that can be modified to enhance the expression of oxacillin resistance include all the following, except

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

What McFarland standard provides turbidity comparable to that of a bacterial suspension containing approximately 1.5 $\times$ 10⁸ colony-forming units (CFU) /mL?

Correct Answer
verified

All the following organisms often produce $\beta$ -lactamase, except

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

A 12-year-old girl goes to the doctor complaining of a sore throat, fever, headache, and general malaise. The doctor does a quick strep test that is positive for group A $\beta$ -hemolytic Streptococcus. No antibiotic testing is needed because Streptococcus is

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified